Remark
External angles added to an internal angle = 180o
Every triangle has 180 degrees.
Step One
Find the supplement of 131: Call the Supplement x
x + 131 = 180
x = 180 - 131
x = 49
Step Two
Find the supplement of 160o. Call that angle y
y + 160 = 180
y = 20
step 3
Find the value of the supplement to n. Remember every triangle has 180 degrees. Call this angle z
x + y + z = 180 degrees
49 + 20 + z = 180
69 + z = 180
z = 180 - 69
z = 111
Step Four
Find the supplement to z (which is n)
z + n = 180
111 + n = 180
n = 180 - 111
n = 69
